【作者】 张毅；

【导师】 陈英奇； 戴立言；

【作者基本信息】 浙江大学 ， 应用化学， 2013， 博士

【摘要】 路易斯酸是有机反应中常用的催化剂,在傅克烷基化和酰基化、酯化、脑文格尔缩合、迈克尔加成、狄尔斯-阿尔德等反应中,表现出优异的催化活性。作为高效均相催化剂,路易斯酸还是有一些不足之处,如腐蚀性、高毒性、副反应多、用量大、后处理产生大量废水。负载路易斯酸是一类清洁、环保的多相催化剂,和均相路易斯酸一样具有催化活性的负载路易斯酸有几个显著的特点：后处理简单、可回收和重复使用、无毒、稳定性好等。通过路易斯酸与树脂络合,制备了树脂负载四氯化钛(Ps-TiCl4)和树脂负载三氯化铁(Ps-FeCl3)。用TGA、BET、SEM、IR.吡啶红外、滴定等分析手段对催化剂进行了表征,滴定实验测定了Ps-TiCl4和Ps-FeCl3的负载量分别为0.35mmol/g和0.30mmol/g。两种催化剂对各种醇和酚的四氢吡喃化反应有很好的催化活性,同时,在两种催化剂存在下,四氢吡喃醚在甲醇中可以顺利的发生去四氢吡喃化反应。反应条件温和、后处理容易、副产物少、产率高是这一催化反应的优点。两种催化剂回收和重复使用5次,依然表现出良好的催化活性。通过氯化铝与树脂络合,制备了树脂负载氯化铝(Ps-AlCl3).用TGA、BET、IR、吡啶红外、滴定等分析手段对催化剂进行了表征,Ps-AlCl3的负载量为0.45mmol/g。无溶剂条件下,Ps-AlCl3可催化醛与1,3-二羰基化合物的脑文格尔缩合反应。这一催化方法简单高效,在Ps-AlCl3催化剂存在下,60℃,2-4h,缩合反应能顺利进行并获得较高的产率(87-98%)。Ps-AlCl3可应用于一系列芳香醛的缩合反应,且具有较好的可回收性,重复使用五次催化活性没有明显的下降。无溶剂条件下Ps-AlCl3能够催化各种胺与含吸电子基团的共轭烯烃的Aza-Michael加成反应。室温下,6mol%Ps-AlCl3,0.8-2h,各种不同的脂肪胺与共轭烯烃反应能以较高产率得到加成产物,然而对于芳香胺,70℃,15mol%Ps-AlCl3,2.1-3h,加成反应才比较理想。利用两类胺不同的反应活性,可以实现化学选择性加成,室温下,将脂肪胺与芳香胺等摩尔混合与共轭烯烃反应,只得到脂肪胺加成产物；同一分子中不同氨基的区域选择性加成也可顺利进行,室温下,只得到脂肪胺基加成产物。PS-AICl3有较好的可回收性,重复使用数次催化活性没有明显的下降。制备了三种新型多相催化剂(AlCl3/壳聚糖、AlCl3/甲壳素、AlCl3/乙酰化甲壳素)。用IR、ICP、BET、SEM和27Al固体NMR对催化剂进行了表征。A1Cl3/甲壳素的负载量为2.54mmol/g,高于硅胶负载氯化铝的负载量。三种催化剂对苯甲醚与苄氯的傅克烷基化及苯甲醚与苯甲酰氯的酰基化反应显示了良好的催化活性。三种催化剂的活性次序为AlCl3/壳聚糖>AlCl3/甲壳素：>AlCl3/乙酰化甲壳素。根据27Al固体核磁谱及三种催化剂的活性顺序,推测在27Al固体核磁谱上0ppm的特征峰是物理吸附的氯化铝而非六配位铝物种,且支持了Dube关于85ppm特征峰是由氯化铝与两个硅羟基接枝的观点。重复使用4次后,三种催化剂还具有催化活性。更多还原

【Abstract】 Lewis acids which are commonly used catalysts in the organic reactions show excellent catalytic activity in Friedel-Crafts alkylations and acylations, esterification, Knoevenagel condensations, Michael additions, Diels-Alder reaction, etc. As efficient homogeneous catalysts, they still have several inadequacies such as being corrosive, high toxicity, side reactions, use of large amount, leading to a large quantity of waste liquid after workup. Supported Lewis acid is a class of clean, environmentally friendly heterogeneous catalysts, supported Lewis acids as active as its homogeneous counterparts have several distinguishing characteristics:easy workup, recyclability, reusability, nontoxicity and good stability, etc.Polystyrene supported TiCl4(Ps-TiCl4) and polystyrene supported FeCl3(Ps-FeCl3) were prepared by coordinating Lewis acids with polystyrene. The catalysts were characterized by TGA, BET, SEM, IR, pyridine-adsorbed IR and titration analysis. Titration experiments determined the loadings of Ps-TiCl4and Ps-FeCl3were0.35and0.3mmol g-1respectively. Both catalysts had good catalytic activity for the tetrahydropyranylation of various alcohols and phenols, at the same time, detetrahydropyranylation of tetrahydropyranyl ethers preceded smoothly in the presence of the two catalysts in methnol. Mild reaction conditions, easy workup, less by-products, high yields are the advantages of the catalytic reactions. Two catalysts can be recovered and reused for five times with good activity.Polystyrene supported AICl3(Ps-AlCl3) was prepared by coordinating aluminum chloride with polystyrene. The catalyst was characterized by TGA, BET, IR, pyridine-adsorbed IR and titration analysis, the loading of Ps-AlCl3was0.45mmol g-1. Knoevenagel condensations of1,3-dicarbonyl compounds with aldehydes could be catalyzed by PS-AICl3under solvent-free conditions. This catalytic method was simple and efficient; the condensations were carried out smoothly with high yields (87-98%) at60℃for2-4h in the presence of the Ps-AlCl3catalyst. Ps-AlCl3could be applicable to the condensations of a series of aromatic aldehydes, and had good recyclability and could be reused five times without apparent loss of activity. Aza-Michael additions of various amines with conjugated alkenes bearing electron withdrawing group could be catalyzed by polystyrene-supported aluminum chloride (PS-AICl3) without the use of any solvents. The aliphatic adducts could be synthesized through additions of various aliphatic amines and conjugated alkenes for0.8-2h using6mol%Ps-AlCl3under room temperature with high yields (91-94%), however, the additions of aromatic amines proceded well only when using15mol%Ps-AlCl3for2.1-3h, under70℃. Using the different reactivities of two types of amines, chemoselective additions were achieved under room temperature, a mixture (1:1) of aromatic amines and aliphatic amines was treated with conjugated alkenes, aliphatic adducts were obtained exclusively; Regioselective additions of two different amino groups in one molecule also proceeded smoothly, the aliphatic adducts were the only products under room temperature. Ps-AlCl3had good recyclability and could be reused several times without apparent loss of activity.Three novel heterogeneous catalysts (AlCl3/chitin, AlCl3/chitosan, AICl3/acetylated chitin) were prepared. The catalysts were characterized by IR, ICP, BET, SEM and27Al solid state NMR. The loading of AlCl3/chitin which was higher than that of silica supported AICl3was2.54mmol/g. The catalysts demonstrated good catalytic activity in Friedel-Crafts alkylation of anisole with benzyl chloride and acylation of benzene with benzoyl chloride. The order of the three catalysts’activity was AlCl3/chitosan>AlCl3/chitin>AlCl3/acetylated chitin. According to the27Al solid state NMR spectra and the order of the three catalysts’activity, we concluded the peak at0ppm in the27Al solid state NMR spectra was attributed to physical adsorbed aluminum chloride not to six-coordinate Al species, and supported the viewpoint of Dube which said peak at85ppm was assigned to an aluminum chloride grafted on two silanol groups. The catalysts still remained active after reuse of four times.更多还原